2405
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 3192
- Proper Divisor Sum (Aliquot Sum)
- 787
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 1728
- Möbius Function
- -1
- Radical
- 2405
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 58
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers m such that Fibonacci(m) ends with m.at n=45A000350
- Expansion of 1/((1-x)^2*(1-x^2)*(1-x^5)).at n=48A001304
- Number of multigraphs with 4 nodes and n edges.at n=20A003082
- Coordination sequence T2 for Zeolite Code AFT.at n=37A008027
- Coordination sequence T1 for Zeolite Code MON.at n=30A008181
- Numbers k such that the continued fraction for sqrt(k) has period 5.at n=48A010337
- Least d for which the number with continued fraction [n,n,n,n...] is in Q(sqrt(d)).at n=48A013946
- Pseudoprimes to base 31.at n=20A020159
- Pseudoprimes to base 38.at n=19A020166
- Pseudoprimes to base 73.at n=34A020201
- Numbers whose base-2 representation is the juxtaposition of two identical strings.at n=36A020330
- Numbers whose base-4 representation is the juxtaposition of two identical strings.at n=36A020332
- Numbers whose base-8 representation is the juxtaposition of two identical strings.at n=36A020336
- a(n) is least k such that k and 7k are anagrams in base n (written in base 10).at n=30A023099
- Convolution of odd numbers and primes.at n=13A023662
- Numbers that are the sum of 2 nonzero squares in exactly 4 ways.at n=5A025287
- Numbers that are the sum of 2 nonzero squares in 3 or more ways.at n=25A025294
- Numbers that are the sum of 2 nonzero squares in 4 or more ways.at n=5A025295
- Numbers that are the sum of 2 distinct nonzero squares in exactly 4 ways.at n=5A025305
- Numbers that are the sum of 2 distinct nonzero squares in 3 or more ways.at n=24A025313